Methods, a wireless device, a radio network node for managing a control block

ABSTRACT

Methods, a wireless device ( 110 ) and a radio network node ( 120 ) for managing a control block are disclosed. An extended Temporary Flow Identifier, eTFI, is assigned to the wireless device ( 110 ) by the radio network node ( 120 ). The radio network node ( 120 ) constructs the control information. The radio network node ( 120 ) performs a bit-wise modulo two addition with a control block and a combination of the eTFI and a pre-determined bit pattern to obtain a modified control block. The radio network node ( 120 ) adds channel coding redundancy. The radio network node ( 120 ) maps the modified control block onto physical resources. The radio network node ( 120 ) sends the modified control block to the wireless device ( 110 ). The wireless device ( 110 ) decodes the received modified control block removing the channel coding redundancy, performs a bit-wise modulo two addition between the modified control block and a combination of the eTFI and a pre-determined bit pattern to obtain a control block. The wireless device ( 110 ) decodes the control block using FIRE-decoding to obtain the control information. The wireless device ( 110 ) determines it is the intended recipient of the control information if the TFI information therein matches its assigned TFI. Corresponding computer programs and carriers therefor are also disclosed.

TECHNICAL FIELD

Embodiments herein relate to wireless communication systems, such astelecommunication systems. In particular, a method and a wireless deviceas well as a method and a radio network node for managing a controlblock are disclosed. Corresponding computer programs and carrierstherefor are also disclosed.

BACKGROUND

Within telecommunication systems, such as within a Global System formobile communications (GSM) Enhanced Data Rates for GSM Evolution (EDGE)Radio Access Network (GERAN) network, so called Packet Switched (PS)Temporary Block Flow (TBF) are used to enable transfer of user databetween e.g. a Radio Base Station (RBS) and a Mobile Station (MS), suchas a wireless device. The PS TBF is assigned a Temporary Flow Identity(TFI) value. The TFI value is uniquely identifying a TBF amongconcurrent TBFs in the same direction, i.e. uplink for transfer of datafrom the mobile station to the radio base station or downlink fortransfer of data from the radio base station to the mobile station,assigned the same Packet Data Channel (PDCH) resources on the samecarrier. The same TFI value may be used concurrently for other TBFs onother PDCH resources in the same direction and for TBFs in the oppositedirection. Hence, a TFI is a unique identifier on a given PDCH resource.This need for TFI uniqueness within the context of any given set of PDCHresources, on a given carrier limits the number of devices that mayshare the same radio resources. In case of devices supporting DownlinkMulti-carrier (DLMC) mode of operation, the limitation will be even moresevere as each downlink TBF supported using DLMC will be assigned theuse of PDCH resources on multiple downlink carriers therebysubstantially increasing the number of devices being assigned the samePDCH resources for any given carrier. The DLMC mode of operation isspecified in Third Generation Partnership Project (3GPP) TechnicalSpecification (TS) 44.060, GERAN, Mobile Station (MS)—Base StationSystem (BSS) interface—Radio Link Control Medium Access Control(RLC/MAC) protocol.

The TFI itself is a 5-bit field encoded as binary number in the range 0to 31, which is typically provided to the MS by the GERAN network uponTBF assignment.

A Radio Link Control (RLC)/Medium Access Control (MAC) block sent on agiven uplink/downlink carrier is associated with a certain TBF. Thereare two types of RLC/MAC blocks; RLC/MAC data blocks and RLC/MAC controlblocks for user data and control information, respectively. A RLC datablock is uniquely identified by the TFI together with the direction inwhich the RLC data block is sent, and a RLC/MAC control block isuniquely identified by the TFI together with the direction in which theRLC/MAC control block is sent. In case Starting Sequence Number(SSN)-based Fast Ack/Nack Reporting (FANR) is used, the TFI identifyingthe TBF being acknowledged is included in the Piggy-backed Ack/Nack(PAN) field. Ack/Nack stands for Acknowledge/Non-acknowledge.

This means that e.g. every time an MS receives a downlink data block orcontrol block on one of its assigned PDCHs of a given carrier, it willuse the included TFI field to determine if the block belongs toany—there can be more than one—of the TBFs associated with that specificMS. If so, the block is obviously intended for the specific MS whereuponthe corresponding payload is decoded and delivered to higher layers, butotherwise discarded. In the uplink direction, the behavior is the same,i.e. network uses the TFI value to identify blocks that belong to thesame TBF. This is an existing mechanism used in GERAN networks forfacilitating the multiplexing of multiple users on the same PDCHresources on a given carrier.

The existing TFI addressing space is considered to be insufficientassuming the current increase of PS traffic observed in GERAN networksover the world. Furthermore, the introduction of DLMC in 3GPP Release 12makes the need to extend the TFI space acute, GP-130662 DLMC—ExtendedTFI Addressing Space, 3GPP GERAN#59, Ericsson & ST-Ericsson herebyincorporated by reference.

In the context of DLMC, GERAN Plenary (GP)-121158 Work Item Description(WID): Downlink Multi Carrier GERAN, 3GPP GERAN#55, Ericsson &ST-Ericsson hereby incorporated by reference, a TFI expansion is neededto increase the TFI addressing space of devices multiplexed on the sameradio resources of a given downlink carrier. Solutions for TFI expansionexist for radio blocks carrying user plane payload, wherein a CyclicRedundancy Check (CRC) code is used solely for error detection, see forexample WO2013/070163, which hereby is incorporated by reference.

3GPP TS 45.003, version 11.1.0, section 6.2.1; GERAN; Channel Codingdescribes a bit-wise modulo two (2) addition (XOR) between a TFI and PANCRC field. According to aforementioned WO2013/070163, this concept isextended to also apply to an extended TFI (eTFI) field and a subset ofthe CRC bits of a RLC/MAC data block header or a subset of the CRC bitsof a PAN field. A solution in aforementioned WO2013/070163 is based onthe observation that a PAN field CRC or RLC/MAC header CRC XOR'ed withan eTFI will only be decodable by a MS assigned the very same eTFI. Asthis prevents legacy mobiles, e.g. multiplexed on the same PDCH as amobile having an assigned eTFI, from successfully performing a CRC checkwhen receiving a PAN field CRC or a RLC/MAC header CRC that has beenXOR'ed with an eTFI, it provides a backwards compatible extension of theTFI identifier space. This is because the impact of the eTFI XOR-ing inthis case is effectively seen as an error pattern by the legacy MS, andsince the CRC code cannot correct errors but only detect them, theresulting CRC check will be erroneous and the legacy MS will discard theradio block.

The solution in aforementioned WO2013/070163 is however not capable ofproviding the desired extension of the TFI space when addressing aFIRE-coded control block or RLC/MAC data block. Remark: “FIRE”, or“Fire”, is the name of a person contributing to the development ofFIRE-codes and FIRE-coding techniques. The desired extension cannot beprovided because the FIRE-code is a class of cyclic block codes usedboth for burst error correction and error detection. The burst errorcorrection capability of the FIRE-code is defined by a length “b” of theshortest uncorrectable burst error, Digital Communications (5thedition), Proakis & Salehi, McGraw-Hill International, ISBN-13:978-0072957167.

As is known in the art, a FIRE-code is a cyclic burst error correctingcode over GF(q) with the generator polynomial g(x)=(x^(2t−1)−1)p(x)

where p(x) is a prime polynomial with degree m not smaller than t andp(x) does not divide x^(2t−1)−1. Block length of the fire code is thesmallest integer n such that g(x) divides x^(n)−1. Here the FIRE code isdefined over a finite field GF(q) of block length n. See alsohttp://en.wikipedia.org/wiki/Cyclic_code and more detailed in “CodeDesign for Dependable Systems: Theory and Practical Applications”, July2006, by Eiji Fujiwara, printed by Wiley, ISBN: 978-0-471-75618-7.

This implies that if the solutions proposed in aforementionedWO2013/070163 would be applied on a FIRE-coded radio block, a legacy MSwould treat the XOR'ed eTFI bits as an error sequence, correct them andthen consider the radio block as valid at which point it coulderroneously act on it, e.g. if the legacy TFI provided in the radioblock header of a FIRE-coded control block addressed to a MS operatingin DLMC mode happens to match the TFI assigned to a legacy MS. Hence, aproblem may be that the intended segregation between legacy and new eTFIaware MSs is broken and an extension of the TFI field is no longerfeasible.

SUMMARY

In view of the above, it has been realized that a solution is missingfor the case of radio blocks carrying control plane payload which arecurrently encoded using a FIRE-code instead of a CRC code. The FIRE-codecan be used for both error detection and error correction.

An object may be to alleviate or at least reduce the above mentionedproblem.

According to a first aspect, the object is achieved by a method,performed by a wireless device, for managing a modified control block.The modified control block carries control information for the wirelessdevice. The wireless device is served by a radio network node. A TFI andan eTFI are assigned to the wireless device by the radio network node.The wireless device receives the modified control block from the radionetwork node. The wireless device performs a bit-wise modulo twoaddition between the modified control block and a combination of itsassigned eTFI and a pre-determined bit pattern to obtain a controlblock. The wireless device decodes the control block using FIRE-decodingto obtain the control information. Furthermore, the wireless device isan intended recipient of the control information when a TFI field of thecontrol information matches the TFI assigned to the wireless device.

According to a second aspect, the object is achieved by a method,performed by a radio network node, for managing a control block for awireless device. The control block carries control information addressedto the wireless device. The wireless device is served by the radionetwork node. A TFI and an eTFI are assigned to the wireless device bythe radio network node. The radio network node constructs the controlinformation, wherein a header portion of the control informationcomprises the TFI assigned to the wireless device. The radio networknode encodes control information, using FIRE-encoding, to obtain aFIRE-encoded control block. The radio network node performs a bit-wisemodulo two addition with the FIRE-encoded control block and acombination of the eTFI assigned to the wireless device and apre-determined bit pattern to obtain a modified control block. The radionetwork node adds channel coding redundancy to the modified controlblock. The radio network node maps the modified control block ontophysical resources. The radio network node sends the modified controlblock to the wireless device.

According to a third aspect, the object is achieved by a wireless deviceconfigured to manage a modified control block for carrying controlinformation for the wireless device. The wireless device is servable bya radio network node. A TFI and an eTFI are assignable to the wirelessdevice by the radio network node. The wireless device is configured toreceive the modified control block from the radio network node, and toperform a bit-wise modulo two addition between the control block and acombination of its assigned eTFI and a pre-determined bit pattern toobtain a control block. Furthermore, the wireless device is configuredto decode the control block using FIRE-decoding to obtain the controlinformation. Furthermore, the wireless device is an intended recipientof the control information when a TFI field of the control informationmatches the TFI assigned to the wireless device.

According to a fourth aspect, the object is achieved by a radio networknode configured to manage a control block for a wireless device. Thecontrol block is capable of carrying control information addressed tothe wireless device. The wireless device is servable by the radionetwork node. A TFI and an eTFI are assignable to the wireless device bythe radio network node. The radio network node is configured toconstruct the control information, wherein a header portion of thecontrol information comprises the TFI assigned to the wireless device.The radio network node is further configured to encode the controlinformation, using FIRE-encoding, to obtain a FIRE-encoded controlblock, to perform a bit-wise modulo two addition with the FIRE-encodedcontrol block and a combination of the eTFI assigned to the wirelessdevice and a pre-determined bit pattern to obtain a modified controlblock. Moreover, the radio network node is configured to add channelcoding redundancy to the modified control block, to map the modifiedcontrol block onto physical resources, and to send the modified controlblock to the wireless device.

According to further aspects, the object is achieved by computerprograms and carriers for computer programs corresponding to the aspectsabove.

The wireless device performs the bit-wise modulo two addition betweenthe modified control block and the combination of its assigned eTFI andthe pre-determined bit pattern to thereby correct the one or more errorsdeliberately introduced when a modified control block is produced. Theone or more errors are deliberately introduced by the radio networknode, by means of the bit-wise modulo two addition between the controlblock and a combination of the eTFI of the target wireless device andthe pre-determined bit pattern, in order to prevent legacy MSs frombeing able to successfully decode the modified control block. Thewireless device decodes the control block using FIRE-decoding to obtainthe control information. After performing the bit-wise modulo twoaddition to correct the deliberately introduced errors, theFIRE-decoding is performed and if found to be successful the wirelessdevice considers itself to be the intended recipient of the controlinformation when the TFI field of the control information matches itsassigned TFI. This may happen when any transmission related errors, i.e.unintended errors, are correctable by the FIRE-decoding. At any rate, alegacy MS will never be able to correct the deliberately introduced oneor more errors and will therefore never erroneously assume the modifiedcontrol block to be addressed to it, since a legacy MS do not performany bit-wise modulo two addition with the combination of the eTFI andthe pre-determined bit pattern as above. Thus, the above mentionedobject is achieved.

An advantage is hence that the eTFI may provide the desired separationbetween legacy and eTFI aware MSs, e.g. the wireless device according toembodiments herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The various aspects of embodiments disclosed herein, includingparticular features and advantages thereof, will be readily understoodfrom the following detailed description and the accompanying drawings,in which:

FIG. 1 is a schematic overview of an exemplifying wireless communicationsystem in which embodiments herein may be implemented,

FIG. 2 is a schematic, combined signaling scheme and flowchartillustrating embodiments of the methods when performed in the wirelesscommunication system according to FIG. 1,

FIG. 3 is a diagram illustrating false detection rate as a function ofFIRE-code correctable burst error length,

FIG. 4 is an overview illustrating information bits, parity bits, theeTFI and the pre-determined bit pattern,

FIG. 5 is a flowchart illustrating embodiments of the method in thewireless device,

FIG. 6 is a block diagram illustrating embodiments of the wirelessdevice.

FIG. 7 is a flowchart illustrating embodiments of the method in theradio network node, and

FIG. 8 is a block diagram illustrating embodiments of the radio networknode.

DETAILED DESCRIPTION

Throughout the following description similar reference numerals havebeen used to denote similar elements, units, modules, circuits, nodes,parts, items or features, when applicable. In the Figures, features thatappear in some embodiments are indicated by dashed lines.

FIG. 1 depicts an exemplifying wireless communication system 100 inwhich embodiments herein may be implemented. In this example, thewireless communication system 100 is a GERAN network. In other examples,the wireless communication network 100 may be any cellular or wirelesscommunication system, such as a Wideband Code Division Multiple Access(WCDMA) network, Wireless Fidelity (Wi-Fi) or the like.

Furthermore, a wireless device 110 and a radio network node 120 areshown in FIG. 1.

In some examples, the radio network node 120 serves the wireless device110. The wireless device 110 and the radio network node 120 are capableof communicating 130 with each other.

The radio network node 120 may comprise a Radio Base Station (RBS) 121and/or a Radio Network Controller (RNC) 122.

Thus, the term “radio network node” may refer to an evolved Node B(eNB), a Radio Network Controller (RNC), a Radio Base Station (RBS), acontrol node controlling one or more Remote Radio Units (RRUs), anaccess point or the like.

As used herein, the term “wireless device” may refer to a userequipment, a machine-to-machine (M2M) device, a mobile phone, a cellularphone, a Personal Digital Assistant (PDA) equipped with radiocommunication capabilities, a smartphone, a laptop or personal computer(PC) equipped with an internal or external mobile broadband modem, atablet PC with radio communication capabilities, a portable electronicradio communication device, a sensor device equipped with radiocommunication capabilities or the like. The sensor may be any kind ofweather sensor, such as wind, temperature, air pressure, humidity etc.As further examples, the sensor may be a light sensor, an electronic orelectric switch, a microphone, a loudspeaker, a camera sensor etc. Theterm “user” may indirectly refer to the wireless device.

FIG. 2 illustrates an exemplifying method according to embodimentsherein when performed in connection with the wireless communicationsystem 100 of FIG. 1.

The wireless device 110 performs a method for managing a modifiedcontrol block and the radio network node 120 performs a method formanaging a control block for the wireless device 110. The modifiedcontrol block carries control information for, e.g. addressed to, thewireless device 110. The wireless device 110 is served by a radionetwork node 120. A Temporary Flow Identifier, TFI, and an extendedTemporary Flow Identifier, eTFI, are assigned to the wireless device 110by the radio network node 120.

The following actions may be performed in any suitable order.

Action 201

In order for the radio network node 120 to control the wireless device110, the radio network node 120 constructs the control information. Aheader portion of the control information comprises a TFI field forcarrying the TFI assigned to the wireless device 110. A control message,e.g. a Packet Timeslot Reconfigure message, and its corresponding headermay together comprise the control information.

The header portion of the control information may further comprise, forexample, a Final Segment (FS) bit used to indicate when a downlinkRLC/MAC control block contains the final segment of an RLC/MAC controlmessage and a Relative Reserved Block Period (RRBP) field used toprovide the wireless device with information about the specific uplinkradio block to use when it sends a response to a polling request.

Action 202

The radio network node 120 encodes control information, usingFIRE-encoding, to obtain a FIRE-encoded control block. The radio networknode 120 adds error correction capability to the control information byincluding a FIRE-code in the FIRE-encoded control block. As a result,the FIRE-encoded control block comprises information bits, representingthe control information, and parity bits in the form of the FIRE-code.Expressed differently, the FIRE-encoded control block comprises thecontrol information and the FIRE-code.

Action 203

In order to prevent a legacy MS from potentially successfully decoding aFIRE-encoded control block, one or more deliberate errors may beintroduced whereby the radio network node 120 performs a bit-wise modulotwo addition with the FIRE-encoded control block and a combination ofthe eTFI assigned to the wireless device 110 and a pre-determined bitpattern. Thus, a modified control block is obtained.

In some examples, the pre-determined bit pattern is applied, e.g. whenperforming the bit-wise modulo two addition, among the parity bits andbits of the eTFI are also applied among the parity bits. This may meanthat the modified control block comprises parity bits. Further, thebit-wise modulo two addition of the combination of the eTFI and thepre-determined bit pattern may be performed using bit positions amongthe parity bits.

Again, expressed somewhat differently, bits of both the eTFI and thepre-determined bit pattern may be applied, such as positioned, atpre-determined bit positions in the control block. If the wirelessdevice 110 is informed about the deliberate introduction of one or moreerrors using the pre-determined bit positions, the wireless device 110may be able to correct these one or more errors.

In order to ensure that the deliberately introduced one or more errorsare not corrected by the legacy MS, the pre-determined bit pattern maybe distributed over a distance being equal to or exceeding a shortestuncorrectable burst error length. In some examples, the shortestuncorrectable burst error length may be 18 bits.

The pre-determined bit pattern may include three bits, wherein each ofthe three bits may be set. When a bit is set it means that the bit isassigned a value of one, or logical one/true. In contrast thereto, whena bit is cleared it means that the bit is assigned a value of zero, orlogical zero/false. This means that for each bit of the control blockthat is XORed with the pre-determined bit pattern, that each bit will beflipped, i.e. modified from set to cleared or from cleared to set. Anybits of the pre-determined bit pattern that are cleared will not providea deliberate error in the control block, since XOR-ing with a zero doesnot provided any flipping of bits. Hence, it may be ensured that thedesired one or more deliberate errors are introduced by XOR-ing usingthe pre-determined bit pattern, which comprises all 1's.

Action 204

The radio network node 120 adds channel coding redundancy to themodified control block according to manners known in the art. A purposeof the channel coding is to make reception, at the wireless device 110,of the modified control block, transmitted by the radio network node 120in action 206, more reliable.

Action 205

The radio network node 120 maps the channel coded modified control blockonto physical resources according to manners known in the art. Thismeans for example that the radio network node 120 determines whichphysical resources, e.g. time and/or frequency resources which may becontinuous or scattered, to use when performing action 206.

Action 206

In order to make the wireless device 110 aware about the controlinformation, the radio network node 120 sends the channel coded modifiedcontrol block to the wireless device 110.

Action 207

When action 206 has been performed, the wireless device 110 receives thechannel coded modified control block from the radio network node 120.

This action may include that the wireless device 110 removes, or channeldecodes, the channel coding redundancy added by the radio network node120 in action 204 thereby producing the modified control block.

Action 208

In order to correct the one or more deliberate errors introduced inaction 203, the wireless device 110 performs a bit-wise modulo twoaddition between the modified control block and the combination of theeTFI and the pre-determined bit pattern to obtain the control block.Expressed differently, the bit-wise modulo two addition may be anXOR-operation. The pre-determined bit pattern may be referred to as abeacon, a beacon bit pattern and the like.

Action 209

The wireless device 110 decodes the control block using FIRE-decoding toobtain the control information. When a successful FIRE-decoding has beenperformed, the FIRE-code of the control block, obtained in action 208,checks, i.e. the FIRE-code of the control block matches with acalculated FIRE-code. The calculated FIRE-code is calculated based onthe control information.

The wireless device 110 is the intended recipient of the controlinformation when the FIRE-decoding is successful and the TFI field ofthe control information matches the TFI assigned to the wireless device110.

This means that, in order for the wireless device 110 to know whetherthe control information is intended for it, the wireless device 110 maycheck a header portion of the control information to read the TFI of thereceived control block. If the TFI in the header portion matches the TFIthat is assigned to the wireless device 110, then the controlinformation is intended for the wireless device 110.

In order to further elaborate on details and describe alternative oradditional embodiments, the following examples are provided. Notably,the pre-determined bit pattern is exemplified by a beacon, beacon bitsor beacon bit pattern.

In a particular embodiment in this disclosure, it is proposed to, whenaddressing a FIRE-encoded radio block, as an exemplifying control block,to a wireless device 110 assigned an eTFI, i.e. a non-legacy MS, XOR theradio block with the eTFI field in combination with a beacon bit patterndistributed over a distance being equal to or exceeding the shortestuncorrectable burst error length b. This approach will secure that alegacy MS, multiplexed on the same PDCH resources as the eTFI capablewireless device 110, cannot successfully FIRE-decode the same modifiedradio block regardless of the eTFI value signaled. The eTFI capablewireless device 110 is aware of this XOR-ing operation, including theknowledge of the specific bits for which the beacon and eTFI XOR-ing hasbeen performed. As such when assigned an eTFI, it can reverse theoperation by performing the XOR operation in conjunction with, e.g.immediately prior to, the FIRE-decoding.

This is equally applicable in the downlink (DL) and in the uplink (UL).The proposed method is not limited to GERAN. It is not limited to signaleTFI information and is applicable to all types of error correctingcodes with pre-determined capabilities, e.g. FIRE-code with the errorcorrecting capability as described above.

In GERAN a number of logical channels such as the Packet AssociatedControl Channel (PACCH) and Slow Associated Control Channel (SACCH), tomention a few, are based on the channel encoding where a shortenedFIRE-code is used, appending a 40 bit parity bit field to 184information bits 3GPP TS 45.003, 3GPP; GERAN; Channel Coding.

These 40 parity bits can either be used to correct or detect errors orboth detect and correct errors. This leads to a delicate tradeoffbetween improved Block Error Rate (BLER) and False Detection Rate (FDR).FDR, or False Positives rate, is referring to a receiver's capability todetect if a received block was erroneous or not. A “false” positiveoccurs when the block received is incorrect and after attempted errorcorrection is still incorrect but is detected as correctly received bythe receiver.

In the case of a GERAN receiver this balance is ultimately determined bya requirement stating that when exposed to a random input signal “theoverall reception performance shall be such that no more than 0.002% ofthe frames are assessed to be error free” 3GPP TS 45.005, 3GPP; GERAN;Radio Transmission and reception. Based on this requirement it can beshown in theory that a GERAN receiver is typically not allowed to beconfigured for correction of burst error sequences of greater lengththan 17 bits.

This is also confirmed in FIG. 3 where FDR is plotted as a function ofcorrectable burst error sequence lengths. When the FIRE-decoder isconfigured to correct error bursts of length 18, or above, the GERAN FDRrequirement of 0.002% is violated. FIG. 3 thus illustrates FalseDetection Rate of a GSM receiver as a function of configured FIRE-codecorrectable burst error sequence lengths when exposed to random input.

In the case of GERAN and a FIRE-encoded radio block, as an example ofthe FIRE-encoded control block, it is sufficient to, in the transmitter,XOR any bit sequence containing at minimum two 1's, designated as beacon1's, separated by at least 17 bits to secure that a legacy MS will notbe able to decode the same radio block. The legacy MS will effectivelyfail to correct the XOR'ed bit sequence, i.e. only one of the XOR'ed 1'scan be corrected by the FIRE-code, and the legacy MS detects thereceived radio block as erroneous. If a target eTFI field is theninserted into the same bit sequence, i.e. in addition to the beacon 1's,and resulting bit sequence is XOR'ed into the FIRE-coded radio block theresulting radio block can be addressed to a wireless device 110 assignedthat target eTFI value as it will be aware of the transmitter havingalready XOR'ed the beacon and target eTFI bit sequence prior totransmission of the modified radio block.

Although the XORed bits can be spread over the entire FIRE-coded radioblock, it is attractive to only apply them over the parity bits. Doingso allows e.g. an eTFI capable wireless device 110 to apply the XORoperation after it has run the FIRE-decoder and thereby produced the setof parity bits applicable to the received modified radio block. If theXOR'ed bit sequence, i.e. the beacon 1's and the eTFI bit pattern, isspread over the entire modified radio block the receiver must apply theXOR operation before it does the FIRE-decoding. In case a receiver isassigned multiple eTFIs for a given set of PDCH resources on a givencarrier this will lead to a higher computational load (iterativedecoding). With this in mind a simple but efficient solution would be todefine the beacon bits as N 1's spread uniformly with equally spacingover the parity field. N eTFI bits can then be inserted adjacent to thebeacon bits. This is illustrated in FIG. 4 assuming N=3 resulting in 3beacon bits and 3 eTFI bits. FIG. 4 illustrates an exampleimplementation of a three bit eTFI field=‘100’, shown in boxes 1, 20,38, along with three beacon 1's and performing the XOR operation overparity bits of a FIRE-encoded radio block.

Different options exist both on how the beacon bits and the eTFI bitscan be placed in a FIRE-encoded radio block. As long as the errorcorrecting capabilities of the underlying code (in the case of GERAN ashortened (224,184) FIRE-code) is not fulfilled by the beacon bits orthe eTFI bits (the bits need to be separated by at least “b” bitpositions), the legacy MS will not be able to successfully read theblock (i.e. it will declare it to be uncorrectable), and will hencediscard it.

It should be noted that the beacon bit pattern is used to secure thateTFI bit patterns of any weight, including zero-weight and single-weightpatterns, can be assigned and signaled to an eTFI capable wirelessdevice. In case it is known that the eTFI signaled contains at least two1's, with an intermediate distance equal to or exceeding the shortestuncorrectable burst error length “b”, then the beacon bit pattern is notrequired to be applied.

Embodiments in this disclosure outline a general method for signaling aninformation field by modifying a FIRE-encoded radio block. In terms ofGERAN, it provides a backwards compatible extension of the TFIaddressing space applicable to FIRE-encoded radio blocks.

In FIG. 5, an exemplifying, schematic flowchart of embodiments of themethod of the wireless device 110 as illustrated in FIG. 2 above isshown. Thus, the wireless device 110 performs a method for managing amodified control block.

As mentioned, the modified control block carries control information forthe wireless device 110. The wireless device 110 is served by a radionetwork node 120. A TFI and an eTFI are assigned to the wireless device110 by the radio network node 120.

Again, the modified control block may comprise parity bits. Thepre-determined bit pattern may be applied among the parity bits. Thepre-determined bit pattern may be distributed over a distance beingequal to or exceeding a shortest uncorrectable burst error length. Theshortest uncorrectable burst error length may be 18 bits. Bits of boththe eTFI and the pre-determined bit pattern may be applied atpre-determined bit positions in the received modified control block. Thepre-determined bit pattern may include three bits, wherein each of thethree bits may be set.

The following actions may be performed in any suitable order.

Action 501

The wireless device 110 receives the modified control block from theradio network node 120. This action corresponds to action 207.

Action 502

The wireless device 110 performs a bit-wise modulo two addition betweenthe modified control block and a combination of its assigned eTFI and apre-determined bit pattern to obtain a control block.

As mentioned, the modified control block may comprise parity bits. Then,the bit-wise modulo two addition of the combination of the eTFI and thepre-determined bit pattern may be performed using bit positions amongthe parity bits.

This action corresponds to action 208.

Action 503

The wireless device 110 successfully decodes the control block usingFIRE-decoding to obtain the control information. The wireless device 110is an intended recipient of the control information when the TFI fieldof the control information matches the TFI assigned to the wirelessdevice 110.

Bits of the eTFI may be applied among the parity bits.

This action corresponds to action 209.

With reference to FIG. 6, a schematic block diagram of embodiments ofthe wireless device 110 of FIG. 1 is shown. The wireless device 110 isconfigured to manage a modified control block for carrying controlinformation for the wireless device 110.

As mentioned, the wireless device 110 is servable by a radio networknode 120. A TFI and an eTFI are assignable to the wireless device 110 bythe radio network node 120.

Again, the modified control block may comprise parity bits. Thecombination of, or only one of, the eTFI and the pre-determined bitpattern may be applied among the parity bits. The pre-determined bitpattern may be distributed over a distance being equal to or exceeding ashortest uncorrectable burst error length. The shortest uncorrectableburst error length may be 18 bits. Bits of both the eTFI and thepre-determined bit pattern may be applied at pre-determined bitpositions in the received modified control block. The pre-determined bitpattern may include three bits, wherein each of the three bits may beset.

The wireless device 110 may comprise a processing module 601, such as ameans, one or more hardware modules and/or one or more software modulesfor performing the methods described herein.

The wireless device 110 may further comprise a memory 602. The memorymay comprise, such as contain or store, a computer program 603.

According to some embodiments herein, the processing module 601comprises, e.g. ‘is embodied in the form of’ or ‘realized by’, aprocessing circuit 604 as an exemplifying hardware module. In theseembodiments, the memory 602 may comprise the computer program 603,comprising computer readable code units executable by the processingcircuit 604, whereby the wireless device 110 is operative to perform themethods of FIG. 2 and/or FIG. 5.

In some other embodiments, the computer readable code units may causethe wireless device 110 to perform the method according to FIGS. 2and/or 5 when the computer readable code units are executed by thewireless device 110.

FIG. 6 further illustrates a carrier 605, comprising the computerprogram 603 as described directly above. The carrier 605 may be one ofan electronic signal, an optical signal, a radio signal, and a computerreadable medium.

In some embodiments, the processing module 601 comprises an Input/Outputunit 606, which may be exemplified by a receiving module and/or asending module as described below when applicable.

In further embodiments, the processing module 601 may comprise one ormore of a receiving module 620, a decoding module 630, and a performingmodule 640 as exemplifying hardware modules. In other examples, one ormore of the aforementioned exemplifying hardware modules may beimplemented as one or more software modules.

Therefore, according to the various embodiments described above, thewireless device 110 is operative to and/or the wireless device 110, theprocessing module 601 and/or the receiving module 620 is configured toreceive the modified control block from the radio network node 120.

The wireless device 110 is operative to and/or the wireless device 110,the processing module 601 and/or the performing module 640 is configuredto perform a bit-wise modulo two addition between the modified controlblock and a combination of its assigned eTFI and a pre-determined bitpattern to obtain a control block.

The wireless device 110 is operative to and/or the wireless device 110,the processing module 601 and/or the decoding module 630 is furtherconfigured to decode the control block using FIRE-decoding to obtain thecontrol information. The wireless device 110 is an intended recipient ofthe control information, e.g. when the FIRE-decoding is successful, anda TFI field of the control information matches the TFI assigned to thewireless device 110.

As mentioned, bits of the eTFI may be applied among the parity bits.

In FIG. 7, an exemplifying, schematic flowchart of embodiments of themethod of the radio network node 120 as illustrated in FIG. 2 above isshown. Thus, the radio network node 120 performs a method for managing acontrol block for a wireless device 110.

As mentioned, the control block carries control information addressed tothe wireless device 120. The wireless device 110 is served by the radionetwork node 120. A Temporary Flow Identifier, TFI, and an extendedTemporary Flow Identifier, eTFI, is assigned to the wireless device 110by the radio network node 120.

Again, the control block may comprise parity bits. The pre-determinedbit pattern may be applied among the parity bits. Bits of the eTFI maybe applied among the parity bits. The pre-determined bit pattern may bedistributed over a distance being equal to or exceeding a shortestuncorrectable burst error length. The shortest uncorrectable burst errorlength may be 18 bits. Bits of both the eTFI and the pre-determined bitpattern may be applied at pre-determined bit positions in the controlblock. The pre-determined bit pattern may include three bits, whereineach of the three bits may be set.

The following actions may be performed in any suitable order.

Action 701

The radio network node 120 constructs the control information, wherein aheader portion of the control information comprises the TFI assigned tothe wireless device 110. This action corresponds to action 201.

Action 702

The radio network node 120 encodes control information, usingFIRE-encoding, to obtain a FIRE-encoded control block. This actioncorresponds to action 202.

Action 703

The radio network node 120 performs a bit-wise modulo two addition withthe FIRE-encoded control block and a combination of the eTFI and apre-determined bit pattern to obtain a modified control block.

As mentioned, the modified control block may comprise parity bits. Then,the bit-wise modulo two addition of the combination of the eTFI and thepre-determined bit pattern may be performed using bit positions amongthe parity bits.

This action corresponds to action 203.

Action 704

The radio network node 120 adds channel coding redundancy to themodified control block. This action corresponds to action 204.

Action 705

The radio network node 120 maps the modified control block onto physicalresources. This action corresponds to action 205.

Action 706

The radio network node 120 sends the modified control block to thewireless device 110. This action corresponds to action 206.

With reference to FIG. 8, a schematic block diagram of embodiments ofthe radio network node 120 of FIG. 1 is shown. The radio network node120 is configured to manage a control block for a wireless device 110.

As mentioned, the control block is capable of carrying controlinformation addressed to the wireless device 120. The wireless device110 is servable by the radio network node 120. A TFI and an eTFI areassignable to the wireless device 110 by the radio network node 120.

Again, the modified control block may comprise parity bits. Thecombination of, or only one of, the eTFI and the pre-determined bitpattern may be applied among the parity bits. Bits of the eTFI may beapplied among the parity bits. The pre-determined bit pattern may bedistributed over a distance being equal to or exceeding a shortestuncorrectable burst error length. The shortest uncorrectable burst errorlength may be 18 bits. Bits of both the eTFI and the pre-determined bitpattern may be applied at pre-determined bit positions in the controlblock. The pre-determined bit pattern may include three bits, whereineach of the three bits may be set.

The radio network node 120 may comprise a processing module 801, such asa means, one or more hardware modules and/or one or more softwaremodules for performing the methods described herein.

The radio network node 120 may further comprise a memory 802. The memorymay comprise, such as contain or store, a computer program 803.

According to some embodiments herein, the processing module 801comprises, e.g. ‘is embodied in the form of’ or ‘realized by’, aprocessing circuit 804 as an exemplifying hardware module. In theseembodiments, the memory 802 may comprise the computer program 803,comprising computer readable code units executable by the processingcircuit 804, whereby the radio network node 120 is operative to performthe methods of FIG. 2 and/or FIG. 7.

In some other embodiments, the computer readable code units may causethe radio network node 120 to perform the method according to FIGS. 2and/or 7 when the computer readable code units are executed by the radionetwork node 120.

FIG. 8 further illustrates a carrier 805, comprising the computerprogram 803 as described directly above. The carrier 805 may be one ofan electronic signal, an optical signal, a radio signal, and a computerreadable medium.

In some embodiments, the processing module 601 comprises an Input/Outputunit 806, which may be exemplified by a receiving module and/or asending module as described below when applicable.

In further embodiments, the processing module 801 may comprise one ormore of a constructing module 810, an encoding module 820, a performingmodule 830, an adding module 840, a mapping module 850 and a sendingmodule 860 as exemplifying hardware modules. In other examples, one ormore of the aforementioned exemplifying hardware modules may beimplemented as one or more software modules.

Therefore, according to the embodiments above, the radio network node120 is operative to and/or the radio network node 120, the processingmodule 801 and/or the constructing module 810 is configured to constructthe control information, wherein a header portion of the controlinformation comprises the TFI assigned to the wireless device 110.

The radio network node 120 is operative to and/or the radio network node120, the processing module 801 and/or the encoding module 820 isconfigured to encode the control information, using FIRE-encoding, toobtain a FIRE-encoded control block.

The radio network node 120 is operative to and/or the radio network node120, the processing module 801 and/or the performing module 830 isconfigured to perform a bit-wise modulo two addition with theFIRE-encoded control block and a combination of the eTFI and apre-determined bit pattern to obtain a modified control block.

The radio network node 120 is operative to and/or the radio network node120, the processing module 801 and/or the adding module 840 isconfigured to add channel coding redundancy to the modified controlblock.

The radio network node 120 is operative to and/or the radio network node120, the processing module 801 and/or the mapping module 850 isconfigured to map the modified control block onto physical resources.

The radio network node 120 is operative to and/or the radio network node120, the processing module 801 and/or the sending module 860 isconfigured to send the modified control block to the wireless device110.

As used herein, the term “processing module” may in some examples referto the processing circuit, such as a processing unit, a processor, anApplication Specific integrated Circuit (ASIC), a Field-ProgrammableGate Array (FPGA) or the like. The processing circuit or the like maycomprise one or more processor kernels. In these examples, theprocessing module is thus embodiment by a hardware module. In otherexamples, the processing module may be embodied by a software module.Any such module, be it a hardware, software or a combinedhardware-software module, may be a determining means, estimating means,capturing means, associating means, comparing means, identificationmeans, selecting means, receiving means, sending means or the like asdisclosed herein. As an example, the expression “means” may be a modulecorresponding to the modules listed above in conjunction with theFigures.

As used herein, the expression “configured to” may mean that aprocessing circuit is configured to, or adapted to, by means of softwareconfiguration and/or hardware configuration, perform one or more of theactions described herein.

As used herein, the term “memory” may refer to a hard disk, a magneticstorage medium, a portable computer diskette or disc, flash memory,random access memory (RAM) or the like. Furthermore, the term “memory”may refer to an internal register memory of a processor or the like.

As used herein, the term “computer readable medium” may be a UniversalSerial Bus (USB) memory, a DVD-disc, a Blu-ray disc, a software modulethat is received as a stream of data, a Flash memory, a hard drive, amemory card, such as a MemoryStick, a Multimedia Card (MMC), etc.

As used herein, the term “computer readable code units” may be text of acomputer program, parts of or an entire binary file representing acomputer program in a compiled format or anything there between.

As used herein, the terms “number”, “value” may be any kind of digit,such as binary, real, imaginary or rational number or the like.Moreover, “number”, “value” may be one or more characters, such as aletter or a string of letters. “number”, “value” may also be representedby a bit string.

As used herein, the expression “in some embodiments” has been used toindicate that the features of the embodiment described may be combinedwith any other embodiment disclosed herein.

Even though embodiments of the various aspects have been described, manydifferent alterations, modifications and the like thereof will becomeapparent for those skilled in the art. The described embodiments aretherefore not intended to limit the scope of the present disclosure.

The invention claimed is:
 1. A method, performed by an eTFI-awarewireless device, for managing a modified control block, wherein themodified control block carries control information for the eTFI-awarewireless device, wherein the eTFI-aware wireless device is served by aradio network node, wherein a Temporary Flow Identifier, TFI, and anextended Temporary Flow Identifier, eTFI, are assigned to the eTFI-awarewireless device by the radio network node, wherein the method comprises:receiving the modified control block from the radio network node,wherein the modified control block comprises a control block that theradio network node has FIRE-encoded and introduced one or more errors toprevent legacy wireless devices from successfully decoding the modifiedcontrol block, wherein the radio network node introduces the one or moreerrors by performing a first bit-wise modulo two addition between theFIRE-encoded control block and a combination of the eTFI and apre-determined bit pattern; performing, by the eTFI-aware wirelessdevice, a second bit-wise modulo two addition between the modifiedcontrol block and the combination of the eTFI and the pre-determined bitpattern to obtain the FIRE-encoded control block and correct the one ormore errors introduced by the radio network node; and decoding, by theeTFI-aware wireless device, the corrected FIRE-encoded control blockusing FIRE-decoding to obtain the control information, wherein theeTFI-aware wireless device is an intended recipient of the controlinformation when a TFI field of the control information matches the TFIassigned to the eTFI-aware wireless device.
 2. The method according toclaim 1, wherein the modified control block comprises parity bits,wherein the bit-wise modulo two addition of the combination of the eTFIand the pre-determined bit pattern is performed using bit positionsamong the parity bits.
 3. The method according to claim 1, wherein thepre-determined bit pattern is distributed over a distance being equal toor exceeding a shortest uncorrectable burst error length.
 4. The methodaccording to claim 3, wherein the shortest uncorrectable burst errorlength is 18 bits.
 5. The method according to claim 1, the bit-wisemodulo two addition of the eTFI and the pre-determined bit pattern isperformed using pre-determined bit positions in the received modifiedcontrol block.
 6. The method according to claim 1, wherein thepre-determined bit pattern includes three bits, wherein each of thethree bits is set.
 7. A computer program product comprising computerreadable program code embedded on a non-transitory memory, the programcode to be executed by at least one processor of an eTFI-aware wirelessdevice for causing the eTFI-aware wireless device to manage a modifiedcontrol block for carrying control information for the eTFI-awarewireless device, wherein execution of the program code causes theeTFI-aware wireless device to perform the method according to claim 1.8. An eTFI-aware wireless device configured to manage a modified controlblock for carrying control information for the wireless device, whereinthe wireless device is servable by a radio network node, wherein aTemporary Flow Identifier, TFI, and an extended Temporary FlowIdentifier, eTFI, are assignable to the wireless device by the radionetwork node, wherein the eTFI-aware wireless device comprises: aprocessing circuit; and a non-transitory memory that stores computerreadable program code; wherein when the processing circuit executes thecomputer readable program code, the eTFI-aware wireless device is causedto: receive the modified control block from the radio network node,wherein the modified control block comprises a control block that theradio network node has FIRE-encoded and introduced one or more errors toprevent legacy wireless devices from successfully decoding the modifiedcontrol block, wherein the radio network node introduces the one or moreerrors by performing a first bit-wise modulo two addition between theFIRE-encoded control block and a combination of the eTFI and apre-determined bit pattern; perform a second bit-wise modulo twoaddition between the modified control block and the combination of theeTFI and the pre-determined bit pattern to obtain the FIRE-encodedcontrol block and correct the one or more errors introduced by the radionetwork node; and decode the corrected FIRE-encoded control block usingFIRE-decoding to obtain the control information, wherein the eTFI-awarewireless device is an intended recipient of the control information whena TFI filed of the control information matches the TFI assigned to theeTFI-aware wireless device.
 9. The eTFI-aware wireless device accordingto claim 8, wherein the modified control block comprises parity bits,wherein the combination of the eTFI and the pre-determined bit patternis applied among the parity bits.
 10. The eTFI-aware wireless deviceaccording to claim 8, wherein the pre-determined bit pattern isdistributed over a distance being equal to or exceeding a shortestuncorrectable burst error length.
 11. The eTFI-aware wireless deviceaccording to claim 10, wherein the shortest uncorrectable burst errorlength is 18 bits.
 12. The eTFI-aware wireless device according to claim8, wherein bits of both the eTFI and the pre-determined bit pattern arepositioned at pre-determined bit positions in the received modifiedcontrol block.
 13. The eTFI-aware wireless device according to claim 8,wherein the pre-determined bit pattern includes three bits, wherein eachof the three bits is set.